MX2013014521A - Absorbent article having intake structure. - Google Patents

Abstract

An absorbent article (1 ) comprising a fluid permeable topsheet (2), a fluid impermeable backsheet (4) and an absorbent core (6) enclosed between the topsheet (2) and the backsheet (4). The absorbent core (6) comprises a first absorbent layer (22) having an opening (25) extending therethrough. A fluid flow control structure (24) is arranged between the first absorbent layer (22) and the backsheet (4). The fluid flow control structure (24) is a layered structure comprising a non-perforated fibrous polymeric layer (31 ) and a first perforated polymeric layer (32) having a basis weight of from 50 g/m2 to100 g/m2.

Description

ABSORBENT ARTICLE WITH ENTRY STRUCTURE TECHNICAL FIELD OF THE INVENTION The invention pertains to an absorbent article comprising a fluid-permeable inner cover, an outer fluid-impermeable cover and an absorbent core attached between the inner cover and the outer cover, the absorbent core comprises a first absorbent layer and comprises an opening that is extends through the first absorbent layer.

BACKGROUND OF THE INVENTION Absorbent articles of the type used in common underpants include incontinence shields and sanitary napkins. Since these items must be measured and configured to fit within the limited space available in the crotch portion of underwear, items are designed by necessity with a relatively small width. For this reason, a particular problem with such articles is that they can leak on the side edges, before the full absorption capacity of the article has been utilized.

Lateral filtration can occur as a consequence of absorbed fluid that disperses just as quickly in all directions from the point where fluid enters the article. This will lead to the fluid escaping from the article by the side edges before it is distributed to the end portions of the article. Another cause of lateral filtration can be when the entry capacity of the article is insufficient to allow all the fluid exuding in the article to enter directly into the article. Instead, the fluid will flow into the outer shell and out through the side edges of the article where it can be filtered out and dirty the user's clothing. Another disadvantage when the fluid flows to The exterior of the outer shell is that a large portion of the outer shell in contact with the body will get wet. This, of course, is highly undesirable since it makes the article unhygienic and unpleasant to use.

Incontinence shields and sanitary napkins are designed to have a total absorption capacity that is large enough to absorb all fluid that is expected to be released to the absorbent article during a period of use. However, the fluid is normally not exuded in a stable flow, but rather as sudden jets of relatively large volume under high pressure and for a short period of time. Accordingly, it would be desirable if the absorbent article were capable of receiving and containing the fluid emitted with the corresponding velocity.

Great efforts have been made in the past to overcome the problem of lateral leakage in relation to disposable absorbent articles such as incontinence shields and sanitary napkins. However, to date, no effort has been completely satisfactory.

International publication WO 2009/105000 discloses a laminated fibrous network having breaks with a decreasing cross-sectional area in a direction of thickness of the network. The network can be used as a fluid entry material and is instructed to improve the flow fluid through the network.

Although the laminate of the prior art can mitigate the problem of lateral leakage to a certain degree, there is still a great need for further improvements in lateral leakage safety for the type of absorbent article that is used in the crotch portion of a garment. inside.

BRIEF DESCRIPTION OF THE INVENTION According to the invention, an absorbent article with improved inlet capacity, fluid distribution properties and leakage safety is provided.

The absorbent article according to the invention has a longitudinal direction and a transverse direction, lateral edges extending in the longitudinal direction and end edges extending in the transverse direction and comprises a fluid-permeable outer cover, an impermeable inner cover to the fluid and an absorbent core attached between the outer shell and the inner shell, the absorbent core comprises a first absorbent layer, the first absorbent layer having an opening extending therethrough. A fluid flow control structure is arranged between the first absorbent layer and the inner cover, the fluid flow control structure is a layered structure comprising a non-perforated fibrous polymeric layer and a first perforated polymeric layer, the first Perforated polymeric layer has a basis weight of between 50 g / m2 and 150 g / m2, preferably a basis weight of between 60 g / m2 and 100 g / m2.

The fluid flow control structure provides the item with high input capacity.

In addition, the article of the invention provides a large empty volume for temporary storage of fluid. The void volume is created either by the hollow space, or formed in the opening in the absorbent layer and internally in the porous fluid flow control structure. As soon as the fluid has entered the fluid flow control structure, it can travel in the open pore structure of the non-perforated layer and can be distributed away from the initially wet area of the absorbent article. The structure Fluid flow control not only improves the transport of fluid away from the initially wetted area but also promotes the distribution of fluid through the absorbent core both in the length direction and in the thickness direction of the article. The thickness of the fluid flow control structure can be less than the thickness of the first absorbent layer, where the fluid dispersion rate changes at the edge of the fluid flow control structure. The fluid flow control structure is preferably a highly porous structure with less resistance to fluid flow than the first absorbent layer, which implies that the fluid will preferably continue to move in the fluid flow control structure. Accordingly, the edges of the fluid flow control structure can act as barriers for fluid distribution transverse to the side edges of the absorbent article, which decreases the risk of lateral leakage.

The opening through the first absorbent layer is preferably placed in the moisture area of the article. The moisture area of the article is the part of the article that is designed to be initially wetted by fluid emitted when the article is used and placed in the crotch area of the absorbent article. By arranging the opening in the first absorbent layer in the moisture area, the emitted fluid can flow directly into the opening and can be collected and temporarily contained in the space defined by the opening and adjacent layers of the absorbent article.

The first absorbent layer in an absorbent article of the invention may have one or more openings. The opening or openings can be of any suitable form or combination of shapes, such as circular, oval, rectangular, square, star, flower, heart, H, T, I, etc. In Consequently, the placement, shape and size of the opening or apertures may vary within the scope of the invention.

Due to its high basis weight and the combination of a perforated layer and a non-perforated layer, the fluid flow control structure will preferably have high strength quality. A high quality of resistance provides the absorbent article with an improved ability to resist transverse compression between the thighs of a user of the article and counteracts undesired deformation of the article during use, so that the opening in the first absorbent layer is kept open for the reception of fluid through the use of the article. The quality of resistance or flexural strength of the laminate material in the fluid flow control structure can be 0.5-5 N, preferably 1-4 N, as measured by the ASTM D 4032-82 CIRCULAR CURVED PROCEDURE. It may be desired that the strength quality of any part of the absorbent article that extends laterally out of the fluid flow control structure has a resistance quality lower than that of the fluid flow control structure where the side portions less Resistant articles of the absorbent article can act as buffer means between the fluid flow control structure and the user's legs.

The absorbent article according to the invention may comprise a second absorbent layer which is arranged between the fluid flow control structure and the inner cover.

The first perforated polymeric layer can be a nonwoven, film or film / non-woven sheet. Preferably, the first perforated polymeric layer is a nonwoven material. Suitable polymers for The first perforated polymeric layer can be polyolefins, polyesters, polyamides and mixtures and combinations of such polymers in preference to polypropylene. The non-woven materials may be bonded materials with carded resin, materials adhered through carded air, non-woven materials consisting of continuous filaments (SMS), carded hydroentangled materials or carded thermosealed materials.

The first perforated polymeric layer may be a three-dimensionally formed layer with penetration openings, the openings extend from a first surface of the layer to a second surface of the layer, which forms protrusions on the second surface and preferably is funnel-shaped. With a funnel-shaped opening used as herein an opening with a narrow shape in its extension direction is implied so that the cross-sectional area of the opening decreases as it moves along the opening.

The first perforated polymeric layer can be arranged with the second surface facing the non-perforated fibrous polymer layer or can be arranged with the second surface facing away from the unperforated fibrous polymer layer.

The first perforated polymeric layer can be arranged as the first layer of the fluid flow control structure, i.e. as the layer of the structure that is located closest to the outer shell.

The apertures in the first perforated polymeric layer can have an average size of 0.5-5 mm, measured in the smaller diameter of the apertures.

The open area of the first perforated polymeric layer may be 5-30%, preferably 10-25%.

The non-perforated fibrous polymer layer can be a long fiber material of 20-120 gsm, preferably 60-100 gsm. The polymer for the non-perforated fibrous polymer layer can be polyester.

The fluid flow control structure can be a three layer structure consisting of the non-perforated fibrous polymer layer, the first perforated polymer layer and a second perforated polymer layer, the non-perforated fibrous polymer layer is placed between the first polymer layer perforated and the second perforated polymeric layer.

The second perforated polymeric layer may be a three-dimensionally formed layer with openings extending from a first surface of the network to a second surface of the network and forming protrusions on the second surface.

The layers in the fluid flow control structure can be attached to each other by means of an adhesive. However, other means for joining the layers as thermal adhesion by hot stamping or ultrasonic adhesion can be used as well as joining layers without using any adhesion means. The fluid flow control structure of the invention has a general planar shape. In particular, the non-perforated fibrous polymer layer should preferably have uniform thickness and a uniform pore structure. The adhesion between the layers should preferably be carried out so that there is minimal impact on the shape and pore structure of the non-perforated fibrous polymer layer.

The polymer materials of the fluid flow control structure can be non-absorbent materials that do not retain any fluid in the material itself. The function of the fluid flow control structure is provide the absorbent article with temporary fluid support capacity and distribute fluid in the article. While the polymer materials in the fluid flow control structure may be hydrophobic, and may have a humidity angle (T) of 90 ° or close to 90 ° which implies that they do not have or have a low wettability when they enter contact with aqueous fluids, it can be an advantage if the components of the fluid flow control structure have been treated at the lowest moisture angle and have become hydrophilic, ie, wettable by body fluids. A perfectly wettable material has a humidity angle (T) of 0o. Any method commonly known for rendering a hydrophilic hydrophobic material can be used, such as treatment with surfactants, plasma or corona treatment, etc.

One aspect of an exemplary embodiment concerns a three-layer fluid flow control structure, wherein both the first perforated polymeric layer and the second perforated polymeric layer can be three-dimensionally formed layers with preferentially funnel-shaped apertures, which are extend from a first surface of the layer to the second surface of the layer and form protrusions on the second surface. Both perforated polymeric layers can be arranged with the second surface facing the non-perforated fibrous polymer layer arranged between the perforated polymer layers.

The apertures in the first and second perforated polymeric layers may be out of register with each other. When the apertures in the first and second perforated polymeric layers are out of register with each other, the fluid prevents one of the layers from passing directly through the thickness of the fluid flow control structure, but is forced to take a more difficult path through the fluid flow control structure. Further, when the fluid enters the fluid flow control structure through a first perforated polymeric layer that is arranged facing the outer cover of the article at least some fluid travels downward toward the inner cover. When the fluid reaches the second perforated polymeric layer and is distributed within the fluid flow control structure, it eventually escapes through an aperture in the second perforated polymeric layer. The second perforated polymeric layer may be a three-dimensional shaped material with apertures forming protrusions on the side of the second perforated polymeric layer that faces the non-perforated fibrous polymeric layer of the fluid flow control structure. In such a case, a network of interconnected channels is formed between the projections in which the fluid network can be captured and can flow a great distance away from the initially wetted area before leaving the fluid flow control structure.

The first and second perforated polymeric layers with three-dimensional shape can be oriented with the apices of the openings, that is, the projections, directed towards the non-perforated fibrous polymer layer or away from the unperforated fibrous polymer layer. The first and second perforated polymeric layers with three-dimensional shape and the long-fiber non-perforated fibrous polymer layer contribute together to the void volume of the fluid flow control structure to contain and move fluid therefrom.

When the fluid flow control structure is a three layer structure of a non-perforated fibrous polymeric layer that is placed between a first perforated polymeric layer and a second perforated polymeric layer, the second perforated polymeric layer may be different from the first layer.

Perforated polymer with respect to chemical composition, physical composition, three-dimensionality, open area, opening size, etc. Otherwise, the second perforated polymeric layer may be identical to the first perforated polymeric layer. The second perforated polymeric layer can therefore have a basis weight, open area and opening size according to the first perforated polymeric layer.

Both perforated polymeric layers can be three-dimensionally formed layers as described herein. Each layer can have penetration openings that originate in a first surface of the layer and extend towards a second surface of the layer, with the vertices of the openings forming protrusions in the second surface of the layer. The openings can be tubular structures and are preferably funnel-shaped with a decreasing cross-sectional area when moving in a direction from the first surface to the second surface of the perforated layer.

Otherwise, one or both perforated polymer layers can be two-dimensional layers. When at least one of the perforated polymer layers is a three-dimensional formed layer, such a three-dimensionally formed perforated layer can be arranged with the first surface facing the non-perforated polymer layer. In an absorbent article according to the invention, a three-dimensionally formed perforated polymer layer is oriented with the projections facing the outer cover of the article which will generally promote the distribution of fluid in the XY plane, i.e., in the longitudinal and cross section of the article, to a degree higher than a perforated polymer layer formed three-dimensionally oriented with the projections facing the inner cover of the article which will generally promote the transport of fluid in the Z direction of the article, i.e., in the thickness direction.

The first and second perforated polymeric layers can pass fluid through them, but act as protective barriers that prevent particles and fibers from entering the fluid flow control structure and interfere with fluid transport within the control structure of the fluid. fluid flow. The particles and fibers may be absorbent materials such as absorbent polymer particles commonly known as "superabsorbents", cellulose filler pulp fibers, etc.

The fluid flow control structure can have a high compressive strength as measured in the Compression Test described herein. Accordingly, the thickness of the flow control structure at 5 kPa can be 60-80% of the thickness at 0.5 kPa in a first, second and third compression made in accordance with the compression test described herein.

In an absorbent article according to the invention, the first absorbent layer may have more than one opening extending therethrough. The openings can be placed in the same general area of the absorbent article, as in two or more of the crotch portion and the end portions. The crotch portion, as used herein, is the portion of the article that is designed to be placed in the crotch of a wearer and to be in contact with the user's pudenda area. The crotch portion includes the moisture area of the article and can be placed asymmetrically in the longitudinal direction of the article. The end portions are placed on each side of the crotch portion in the longitudinal direction of the article. The article can be designed with end portions that are specifically adapted to stand towards the front or the back of a user and can then differ in size, shape, etc., to allow a user to apply the item in a correct way within of the underwear.

The absorbent article of the invention can be provided with means for fixing the article in common underwear or other support pant garment. The fastening means may be adhesive fasteners, friction fixers, mechanical fasteners such as the hook part of a sail fastener, or combinations of different types of fasteners, as is known in the art.

The absorbent article can be a diaper of the open type which is fastened around the lower torso of a wearer by means of belt fasteners, belts or the like or can be a closed type diaper. The absorbent article may be in another form of a type that is used within a support pant or with a support, such as a sanitary napkin, a protective towel or an incontinence protector. Preferably, the absorbent article is an incontinence protector.

An absorbent article according to the invention may comprise a fluid permeable outer cover, disposed on the surface of the incontinence guard which is intended to face a wearer of the incontinence guard, an inner cover disposed on the surface of the incontinence guard which They aim to face the user's underwear, and an absorbent core, attached between the outer cover and the inner cover.

The coverage can be of a type where the outer cover and the The inner cover of the incontinence guard extends laterally together outside the absorbent core along the entire circumference of the absorbent core and connects together at an edge joint around the periphery of the absorbent core. An edge joint can be formed in any suitable manner as is known in the art as by adhesion, ultrasonic adhesion, thermal adhesion, suture, etc. Alternative cover arrangements such as wrapping covers are also conceivable within the scope of the invention.

The outer cover may consist of any material that is suitable for the purpose. Examples of commonly found outer covering materials are nonwoven materials, perforated plastic films, textile or plastic mesh and layers of fluid permeable foam. Laminates consisting of two or more outer cover materials are also commonly used, as are the outer covers of different materials within different parts of the surface facing the fluid-permeable user. The outer cover is preferably a non-woven, non-woven net.

The inner cover is preferably impermeable to the fluid. However, outer cover materials that are only resistant to fluid penetration can be used particularly in instances where relatively small amounts of urine are expected to be carried by the incontinence guard. The inner cover may be thin, flexible, fluid-proof plastic film, but fluid impervious nonwoven materials, fluid impervious gums and fluid impervious sheets are also contemplated within the scope of the invention. The inner cover can be breathable, which implies that air and steam can pass through the inner cover. In addition, the inner cover may have an outer surface, facing the garment of a textile material such as a nonwoven.

The absorbent core can be composed of any suitable fluid accepting material or absorbent known in the art, such as one or more layers of cellulose filler pulp, foam rubber, fiber fillers, etc. The absorbent core may contain fibers or particles of highly absorbent polymer material, commonly known as superabsorbents, which are materials that have the ability to absorb and retain large amounts of fluid in the formation of a hydrogel. The superabsorbents can be mixed with cellulose filler pulp and / or can be arranged in pockets or layers in the absorbent core. The absorbent core may also incorporate components to improve the properties of the absorbent core. Some examples of such components are binder fibers, fluid dispersion materials, fluid acquisition materials, etc., as are known in the art.

The absorbent article may comprise more than one absorbent core. The nuclei can be a higher major nucleus and a lower minor nucleus.

The article may also comprise components such as elastic elements. The elastic elements can be arranged along side edges of the absorbent article. The elastic elements arranged along the lateral edges of the absorbent article improve the anatomical fit of the article by inducing the longitudinal flexure of the article in conformation with the curvature in a crotch of a wearer.

When the absorbent core comprises a first layer Absorbent and a second absorbent layer, the fluid flow control structure can be arranged between the first absorbent layer and the second absorbent layer. The first absorbent layer can be placed underneath and in direct contact with the outer cover. Otherwise, the first absorbent layer can be placed in indirect contact with the outer cover through one or more intervening components such as fabric layers, acquisition layers or other absorbent layers. Similarly, the second absorbent layer can be placed directly below the fluid flow control structure and in direct contact with the fluid flow control structure and the inner cover, but may otherwise be in indirect contact with one or both components by intervention components.

The absorbent layers of the core can be homogeneous structures or can themselves be layered structures such as absorbent sheets or the same or different materials. The absorbent layers may have uniform thickness or may vary in thickness in different parts of the layers. Similarly, the basis weight and composition may vary within the absorbent layers. By way of example, an absorbent layer may comprise a mixture of absorbent and / or non-absorbent fibers and superabsorbent material, wherein the ratio of superabsorbent material to fibers may vary in the layer.

The fluid flow control structure may be rectangular in shape and may be surrounded in the longitudinal and lateral directions by portions of the absorbent core. Although other shapes and configurations for the fluid flow control structure can be used, it is generally favorable if the fluid flow control structure has the same thickness or less than the absorbent core and also the same length or less than the absorbent core. The fluid flow control structure has a highly porous internal structure with less resistance to fluid flow than conventional absorption materials. This means that the fluid dispersion rate changes at the edge of the fluid flow control structure so that the fluid that reaches the edge will continue to move mainly in the fluid flow control structure where the flow resistance is low before being absorbed by the core material. In this way, the edges of the fluid flow control structure act as barriers for the distribution of fluid transversely to the side edges of the absorbent article, therefore decreasing the risk of lateral failure. Conventional absorption materials such as cellulose filler pulp and superabsorbents have comparatively smaller capillaries than the fluid flow control structure. A fibrous structure with fine capillaries has a low fluid acceptance capacity, but has high fluid retention capacity once the fluid has entered the structure. A superabsorbent material has an even lower acceptance rate and higher retention capacity than fibrous absorbent structures due to the acceptance of fluid in such materials that are mainly driven by osmotic pressure.

The components in the absorbent article can be connected together by conventional means such as construction adhesive, heat adhesion, ultrasonic adhesion, etc. It may not be necessary to adhere internal components of the absorbent article to each other by special adhesion means. Consequently, it can satisfy that such components are held together by frictional forces.

TEST METHODS THE CIRCULAR CURVED PROCEDURE ASTM D 4032-82 modified Apparatus: The device is a Circular Bending Resistance Evaluator, which has the following parts: A platform of polished steel plate of smooth shape that has 102.0 x 102.0 x 6.35 mm that has a hole diameter of 18.75 mm. The flap edge of the hole should be at an angle of 45 degrees to a depth of 4.75 millimeters.

A plunger having a general length of 72.2 millimeters, a diameter of 6.25 millimeters, a ball point having a radius of 2.97 millimeters and a needle point extending 0.88 millimeters from it having a base diameter of 0.33 millimeters and A tip that has a radius of less than 0.5 millimeters, the plunger is mounted concentric with the hole and has equal space on all sides. It is noted that the needle tip is merely to prevent lateral movement of the test specimen during the test. Therefore, if the needle tip significantly affects the test specimen (for example, it pierces an inflatable structure) then the needle tip should not be used. The bottom of the plunger should be set well above the lid of the orifice plate.

From this position, the downward stroke of the ball tip is at the exact bottom of the plate hole.

A force measurement meter and more specifically an Instron inverted compression load cell. The load cell has a load range of 0.0 to 10 N.

An actuator, and more specifically an Instron ™ evaluator that has an inverted compression load cell. The Instron ™ tester is manufactured by the Instron Engineering Corporation, Canton, Massachusetts.

Number and preparation of specimens: To perform the procedure for this test, 10 test specimens of 37.5 x 37.5 mm are cut from the laminated test material.

Process: The procedure for the CIRCULAR CURVED PROCEDURE is as follows. The specimens are conditioned by leaving them in a room that is 21 ± 1 o and 50 ± 2% relative humidity for a period of two hours. The test plate is leveled. The piston speed is set to 50.0 centimeters per minute per full strike length. A specimen is centered on the orifice platform below the plunger so that the body surface of the specimen faces the plunger and the pledge surface faces the platform. The zero indicator is revised and adjusted, if necessary. The piston is activated. Touching the specimen during the test should be avoided. The maximum force reading is recorded to the nearest gram. The previous steps are repeated until all five identical specimens have been evaluated.

Compressibility Process: The principle of the method is to slowly compress a material with a metal rod at a force of 5 N while continuously measuring the thickness of the material. The result consists of the data points for force and extension. The force is transmitted at a pressure given the contact area of the rod. The metal rod is cylindrical and has a diameter of 10 mm with a flat base. The rod is mounted in a 10N load cell in the upper installation of an Instron evaluation device. A flat plate is mounted in the bottom installation and is centered under the rod so that a sample can be placed on top of the plate and compressed without movement of the plate. The rate of movement of the rod is 5 mm per minute. These settings have been previously programmed in an Instron Bluehill program called "New Mecano 5 N", but before performing the test, the program settings should be revised to ensure that all limits are set at their proper values. Running with a modified version could lead to damage to the equipment, especially the sensitive load cell.

Run a test: The first execution is an empty execution without proof. This execution is used to find the position of zero thickness, which is where the steel plate stops the rod. The empty execution commonly generates forces higher than the maximum limit established before the rod stops, due to the rapid increase in force that occurs when the rod hits the metal and for which the apparatus can not compensate sufficiently fast. Care must be taken to determine that the load cell can withstand the impact without being damaged. You can use special settings for the empty run for decrease the maximum limit force and the speed of the rod.

When the rod stops, the Instron team waits for the user to enter. The extension then manually restarts to zero. This ensures that the extension is set to zero at the exact correct point where the rod touches the base and the extension is measured relative to the bottom plate. The rod can then be manually moved upwards so that a sample can be placed on the lower plate.

To evaluate a sample, the rod moves manually so that it is above the surface of the sample and the program starts. The rod moves below at a speed of 5 mm per minute until the limit force is reached.

Samples: The samples are square with 50 millimeters of side drilled from the test material. If the material has varying thicknesses, the samples are taken from the thickest parts of the material. The rod is pressed in the center of the sample and each sample is tested three times without moving between executions. Ten samples of each evaluated material are used, giving thirty measurements in total.

Results: The result is the complete set of data points for force against extension. The force is normally recalculated in pressure by means of the measured force divided by the bottom area of the rod. The result can be plotted and reported or you can choose a specific pressure and the thickness noted, so that the result is a thickness for a given pressure.

Measurement of hole diameter and open area The following method can be used to determine the open area and hole diameter for an open material: Apparatus: a Nikon microscope a personal computer NIS software elements BR 3.10 Process: Collect a sample of the open material place the sample on the microscope reading surface start the software take a representative image of the sample perform the analysis of the properties when contrasting the technique that involves highlighting the areas occupied by the holes. The software calculates the diameters of the highlighted holes as diagonal greater and diagonal smaller than a diamond inscribed in the hole. The radius between the diameters is used to determine the actual average conformation of the holes to a circular shape, where a ratio of 1 implies a perfectly circular shape.

The average hole area value obtained by means of the software is used to calculate the percentage of open area.

Alternative methods can be used to determine the diameter of open area and hole, as manual methods and methods based on scanning electron microscopy.

BRIEF DESCRIPTION OF THE FIGURES The invention will be described in more detail below with reference to the figures shown in the attached illustrations.

Figure 1 shows an incontinence protector according to the invention, seen from the side that will give the face intimate garment when the incontinence protector is worn; Figure 2 shows a cross section through the incontinence guard in figure 1, taken along the line ll-ll; Figure 3 shows a section through a fluid flow control structure according to the invention; Figure 4 shows an unfolded perspective view of a fluid flow control structure according to the invention; Y Figure 5a a Figure 5d show absorbent layers having openings therein.

DETAILED DESCRIPTION OF THE INVENTION The absorbent article of the invention is exemplified by an incontinence guard as shown in Figure 1 and Figure 2. It will be understood that the invention is equally applicable to any type of hygienic absorbent article. Such items include incontinence guards, sanitary napkins, protective towels, diapers with tape fasteners, brief-type diapers or belt diapers.

Figure 1 shows a urine incontinence shield 1 seen from the side of the incontinence shield 1 which is intended to face towards a body of a user when the incontinence protector 1 is used.

The incontinence protector 1 comprises a fluid-permeable outer cover 2, an inner cover 4 and an absorbent core 6, included between the outer cover 2 and the inner cover 4.

The outer cover 2 and the inner cover 4 of the incontinence guard 1 are shown to extend laterally together outside the absorbent core 6 along the entire circumference of the absorbent core and connect to each other at an edge joint 7 around the periphery of the absorbent core 6.

The outer cover 2 and the inner cover 4 may consist of any material suitable for the particular purpose, as described herein.

The incontinence guard 1 as shown in Figure 1 and Figure 2 has a generally rectangular elongated shape when fully extended in all directions. The word "generally" in this context means that, for example, the corners of the incontinence guard 1 may be round, or that the edges of the incontinence guard 1 may not be completely linear as illustrated in Figure 1. The shape of the incontinence guard 1 shown in Figure 1 does not it should be considered that it limits the invention. Consequently, any other suitable shape could be used, such as an hourglass shape, trapezoidal shape, triangular shape, oval shape, etc. The shape of the article of the invention may be symmetrical about a transverse center line through the article, as shown in Figure 1 or may be asymmetric with end portions with different shapes and / or different sizes.

The incontinence guard 1 in Figure 1 and Figure 2 has two longitudinal side edges 8, 9 with equal length and extending generally in the same direction as a longitudinal center line 10 through the incontinence guard 1. The edges of Front and rear end 11, 12 extend transversely to the longitudinal center line 10 at the ends of the incontinence guard. The trailing end edge 12 is intended to be oriented rearwardly during the use of the incontinence guard 1, and the front end edge 11 is intended to face forward towards the user's abdomen.

The incontinence guard 1 has a front end portion 13, a rear end portion 14 and a crotch portion 15 located intermediate to the end portions 13, 14. The crotch portion 15 is the portion of the incontinence guard 1 that it is intended to be placed against the crotch of a user during the use of the protector 1 and to constitute the main acquisition area for body fluid that reaches the protector 1.

The incontinence protector 1 also has fixing means 16 for fixing the incontinence protector 1 inside a support pant garment, such as a pair of underpants. The fixing means 16 is in the form of two bands of pressure sensitive adhesive extending longitudinally arranged on the garment facing surface of the inner cover 4. In Figure 2, the fixing means 16 is shown covered by a releasable protective layer 17. The protective layer may be a silicone, non-woven paper or any other releasable material known in the art. Before placing the incontinence protector on the support pant, the protective layer is removed from the fixing means 16 to expose the adhesive and make it available to attach to the trouser press.

The fixing means 16 is optional to the invention and can be omitted, if desired. When an adhesive fixing means is used, any suitable adhesive pattern can be used as a complete covering of the inner cover, one or more longitudinal adhesive bands, cross bands, dots, circles, curves, stars, etc. In addition, the fastening means 16 can be a mechanical fastener such as hook-type fasteners, clamps, pressure bolts, etc., or it can be a friction fixer such as a friction coating or open cell foam rubber. Combinations of different types of fasteners are also conceivable.

The absorbent core 6 of the incontinence guard 1 shown in Figure 1 and Figure 2 comprises a first absorbent layer 22 and a second absorbent layer 23. A fluid flow control structure 24 is arranged between the first absorbent layer 22 and the second one. absorbent layer 23. In the incontinence guard 1 in Figure 1 and Figure 2, the first absorbent layer 22 is placed below and in direct contact with the outer cover 2. Alternate arrangements may be used, as described herein.

The first absorbent layer 22 and the second absorbent layer 23 are shown to have generally rectangular shapes. The second absorbent layer 23 is placed below the first absorbent layer 22. The second absorbent layer 23 is somewhat smaller than the first absorbent layer 22 so that the first absorbent layer 22 extends beyond the second absorbent layer 23 towards forward and backward in the incontinence guard 1. The size and shape of the absorbent layers may be different from those shown in the figures without departing from the invention.

In addition, the second absorbent layer 23 may be omitted in the absorbent article according to the invention or the article may comprise one or more additional absorbent layers.

The first absorbent layer 22 has an opening 25 that extends completely through the layer 22 in the crotch portion 15 of the incontinence guard 1. The opening 25 has an elongated shape. Without deviating from the invention, the shape, size and location of the opening 25 in the first absorbent layer 22 may be different from that shown in Figure 1, as described herein.

The outer cover 2 is shown to extend below in the cavity 26 which is defined by the opening 25 in the first absorbent layer 22 and the surface facing the outer cover of the fluid flow control structure 24. The cavity 26 it is located in the moisture area of the incontinence shield 1 and in use will be placed directly under the urethra and vaginal opening of a female user. Any body fluid that is released to the incontinence guard 1 will be collected directly in the cavity 26 and temporarily contained therein until further distributed within and through the absorbent core 6.

A portion of the fluid that is collected in the cavity 26 can be absorbed by the first absorbent layer through the walls of the cavity 26. However, most of the fluid will continue to fall in the incontinence guard 1, through the bottom of the cavity 26 and within the fluid flow control structure 1 where it is distributed longitudinally and laterally along the flow control structure 24, as described in more detail with reference to Figure 3 and Figure 4.

The fluid flow control structure 24 is shown in Figure 1 in rectangular shape and surrounded in the longitudinal and lateral directions by portions of the absorbent core 6. It is generally favorable if the fluid flow control structure 24 has a smaller thickness and preferably it is also shorter than the absorbent core 6.

The components in the incontinence guard 1 can be connected together by conventional means such as construction adhesive, heating adhesive, ultrasonic adhesive, etc. It may not be necessary to adhere internal components of the incontinence guard to each other by special adhesion means. Therefore, it may be sufficient that such components abut one another by frictional forces.

The function of a fluid flow control structure 24 according to the invention and which is useful in an absorbent article so that the incontinence guard 1 in Figure 1 and Figure 2 will now be described with reference to Figure 3 and Figure 4. The fluid flow control structure 24 in Figure 3 and Figure 4 is a three layer structure consisting of a non-perforated fibrous polymeric layer 31 which is placed between a first perforated polymeric layer 32 and a second perforated polymeric layer 33.

The perforated polymer layers 32, 33 are three-dimensionally formed layers. Each layer 32, 33 has penetration openings 34 that originate in a first surface 32 ', 33' of the layer and extend to a second surface 32", 33" of the layer, with the apices of the openings 34 forming protrusions. 35 on the second surface 32", 33". The openings are tubular structures and preferably have a funnel shape as seen in Figure 3. The distance between the first surface 32 ', 33' and the second surface 32", 33" is the apparent thickness of the respective layers 32, 33.

When the fluid 36 reaches the first surface 32 'of the first perforated polymeric layer 32, it is slightly distributed on the surface 32' before passing through the apertures 34 in the non-perforated fibrous polymeric layer 31 as shown in Figure 3 The unperforated fibrous polymeric layer 31 offers very little resistance to fluid flow, where the fluid advances relatively freely in the layer 31 until finally it moves by gravity under the second perforated layer 33 where another downward movement is restricted by the second surface 33"of the second perforated layer 33. A small amount of fluid can advance out of the fluid flow control structure 24 as it enters the openings in the vertices of the projections 35 in the second perforated layer 33. However, the Most of the fluid will spread beyond the second surface 33"of the second layer 33 as it advances in the network of interconnected channel 37 that is formed between the projections 35, as illustrated in figure 4.

The fluid that is captured in the interconnected channel network 37 will generally not leave the fluid flow control structure 24 until it reaches the edges of the fluid flow control structure 24 or when the channel network 37 is saturated with liquid. fluid so that the fluid level rises above the height of the projections 35. Accordingly, the fluid 36 will be distributed along the second surface 33"in all directions from the initial point of fluid impact. 34 can be distributed in the perforated polymeric layers 32, 33 so that the fluid dispersion takes place to a greater degree in a direction corresponding to the longitudinal direction of the absorbent article in which the fluid flow control structure 24 is placed plus in a direction transverse to it. As shown in Figure 4, the perforated polymer layers 32, 33 have openings 34 arranged in staggered rows, so that generally linear channels are formed between the apertures 34 in a longitudinal direction L of the layers 32, 33 and non-linear channels they are formed in the transverse direction T. Such arrangement of the apertures 34 in the second perforated polymeric layer 33 serves to promote longitudinal fluid flow in the fluid flow control structure and limit the transverse fluid flow.

From Figure 5a to Figure 5d illustrate that the first absorbent layer in an absorbent article of the invention may have one or more openings of different shapes and configurations. The particular configurations shown in Figure 5a to Figure 5d should not be considered as limiting the invention, but are only offered as examples of the many variations that are possible within the scope of the invention. Figure 5a shows a first absorbent layer having multiple circular openings in the crotch portion of the layer. Figure 5b shows a first absorbent layer having three elongated openings in the front portion of the layer and a single elongated opening in the rear portion of the layer. Figure 5c shows a first absorbent layer having an opening formed as a duck foot and figure 5d shows a first absorbent layer having an H-shaped opening. The layer shown in figure 5a can, for example, be suitable when a long total opening area is desired without compromising the desire to have a consistent layer that will not crumble or otherwise deform during the production of the absorbent article according to the invention. A layer as shown in figure 5b and in the Figure 5c and having a large open area placed on the front, can be particularly useful in sanitary napkins for daytime use. The layer of Fig. 5b would work additionally well on absorbent articles that are intended for nighttime use where the fluid can advance backward between the wearer's gluteus. The layer of Figure 5d may be particularly suitable for incontinence guards where it may be desired to rapidly route fluid from the crotch portion of the absorbent article to the ends thereof.

From Figure 5a to Figure 5d they are also intended to show that the first absorbent layer, as well as the absorbent article in general, can have any suitable shape, as is known in the art.

Claims (1)

1. CLAIMS 1. An absorbent article having a longitudinal direction and a transverse direction, lateral edges extending in the longitudinal direction and end edges extending in the transverse direction and comprising a fluid-permeable outer cover, an inner cover impervious to the fluid and an absorbent core included between said outer cover and said inner cover, said absorbent core comprises a first absorbent layer having an opening extending therethrough, characterized in that a fluid flow control structure is arranged between said first layer absorbent and said inner cover, said fluid flow control structure is a layered structure comprising a non-perforated fibrous polymeric layer and a perforated first polymeric layer, said first perforated polymeric layer having a basis weight of between 50 g / m2 and 150 g / m2 2. An absorbent article according to claim 1, characterized in that the first perforated polymeric layer has a basis weight between 60 g / m2 and 100 g / m23. An absorbent article according to claim 1 or 2, characterized in that the first perforated polymeric layer is a nonwoven sheet, film or nonwoven sheet, the first perforated polymeric layer is preferably a nonwoven material. 4. An absorbent article according to claim 1, 2 or 3, characterized in that the first perforated polymeric layer is a three-dimensionally formed layer having penetration openings, the apertures are preferably funnel-shaped and extend from a first surface of said layer towards a second surface of said layer and form protrusions on the second surface. 5. An absorbent article according to claim 4, characterized in that said first perforated polymeric layer is arranged with said second surface facing the non-perforated fibrous polymeric layer. 6. An absorbent article according to claim 4, characterized in that the first perforated polymeric layer is arranged with the second surface facing away from the unperforated fibrous polymer layer. 7. An absorbent article according to any of the preceding claims, characterized in that the average size of the apertures in the first perforated polymeric layer is 0.5-5 mm. 8. An absorbent article according to any of the preceding claims, characterized in that the open area of said first perforated polymeric layer is 5-30%, preferably 0-25%. 9. An absorbent article according to any of the preceding claims, characterized in that the fluid flow control structure is a three layer structure consisting of the non-perforated fibrous polymeric layer, said first perforated polymeric layer and a second perforated polymeric layer, said non-perforated fibrous polymeric layer is placed between the first perforated polymeric layer and said second perforated polymeric layer. 0. An absorbent article according to claim 9, characterized in that said apertures in the first and second perforated, pluripotent layers are out of register with each other. 1 1 An absorbent article in accordance with the claim 9 or 10, characterized in that the second perforated polymeric layer has a basis weight of 50 g / m2 to 150 g / m2, preferably a basis weight of 60 g / m2 to 100 g / m2. 12. An absorbent article according to claim 9, 10 or 11, characterized in that the second perforated polymeric layer is a three-dimensionally formed layer having openings extending from a first surface of said layer to a second surface of said layer and forming outgoing on said second surface. 13. An absorbent article according to claim 12, characterized in that the second perforated polymeric layer is arranged with the second surface facing the non-perforated fibrous polymeric layer. 14. An absorbent article according to claim 12, characterized in that the second perforated polymeric layer is arranged with the second back surface from the unperforated fibrous polymeric layer. 5. An absorbent article according to any of claims 9-14, characterized in that the average size of the apertures in the second perforated polymeric layer is 0.5-5 mm. 16. An absorbent article according to any of claims 9-15, characterized in that the open area of the second perforated polymeric layer is 5-30%, preferably 10-25%. 17. An absorbent article according to any of the preceding claims, characterized in that the second perforated polymeric layer is a nonwoven film or film / nonwoven sheet, the second perforated polymeric layer is preferably a nonwoven material. 18. An absorbent article in accordance with any of the previous claims, characterized in that a second absorbent layer is arranged between said fluid flow control structure and the inner cover. 19. An absorbent article according to any of the preceding claims, characterized in that the thickness of the flow control structure at 5 kPa is 60-80% of the thickness at 0.5 kPa in a first, second and third compression made in accordance with the compression test described herein. 20. An absorbent article according to any of the preceding claims, characterized in that the resistance quality of the laminate material in said fluid flow control structure is 0.5-5 N, preferably 1-4 N, as measured by the PROCEDURE OF CURVED CIRCULAR ASTM D 4032-82 modified. 21. An absorbent article according to any of the preceding claims, characterized in that the basis weight of the non-perforated fibrous polymer layer is 20-120 gsm, preferably 60-100 gsm.